201*316
=(200+1)*316
=200*316+316
=63516
374-205+226-95
=(374+226)-(205+95)
=600-300
=300
3000-999
=3000-1000+1
=2001
997*7+21
=997*7+3*7
=(997+3)*7
=7000
102*99
=102*(100-1)
=102*100-102*1
=10098
2*125
=2*(100+20+5)
=2*100+2*20+2*5
=250
645+80-245
=645-245+80
=480
382*101-382
=382*(101-1)
=38200
4*60*50*8
=(4*60)*(50*8)
=240*400
=96000
25*125*32
=25*125*8*4
=(25*4)*(125*8)
=100*1000
=100000
（29*125）*8
=29*(125*8)
=29*1000
=29000
=(400+4)*25
=400*25+4*25
=10000+100
=10100
156*101-156
=156*101-156*1
=156*(101-1)
=15600
102*32
=(100+2)*32
=100*32+2*32
=3264
125*17*8
=(125*8)*17
=17000
324+92+276-92
=(324+276)+(92-92)
=600
26*99
=26*(100-1)
=26*100-26*1
=2600-26
=2574
125*89*8
=(125*8)*98
=98000
99+49*99
=99*1+49*99
=99*(1+49)
=4950
125*47-47*25
=47*(125-25)
=4700
87*470+870*5
=870*47+870*5
=870*(47+5)
（55+55+55+55*5）*125
=(55*8)*125
=55*(8*125)
=55000
